The present disclosure relates, in general, to vehicle cooling system thermostats.
A thermostat is employed in vehicle cooling systems to control the flow of engine coolant to a heat exchanger or radiator. The thermostat is normally closed blocking flow to the radiator immediately after an engine is started when the engine coolant is at a relatively low or cold temperature. When a predetermined higher or hot temperature is reached, the thermostat opens allowing coolant to flow to the radiator to take advantage of the heat exchange properties of the radiator so as to maintain the engine coolant at a substantially constant temperature during continuous engine operation.
While thermostats are usually reliable in operation, they can still fail. A typical thermostat failure results in the thermostat being disposed in the coolant a flow blocking position preventing coolant flow to the radiator. This can lead to catastrophic engine failure due to extreme engine overheating.
It would be desirable to provide a fail safe engine coolant thermostat which, in the event of a thermostat failure, still allows engine coolant flow to the radiator.